backfire

[simony]

1.9 DF watercooled runs fine except when ticking over cuts out occasionally and backfires when changinging down through the gears could it be the idle stabiliastion unit any ideas ?
thanks

[jason k]

minor air leak at the inlet manifold or carb gaskets at a guess.

or a leaking joint on the exhaust allowing air in on the overrun.

any popping at light throttle??

[simony]

yeah slightly

[jason k]

sounds like an inlet gasket gone. when the motor is running at idle spray some wd 40 around the base of the carb and see if the engine note alters. if it is the gasket will be shot. if not try the inlets on the manifold. carefull if the motors hot tho!!!!

[simony]

it was the gasket between the carb and the in-let manifold big split was wobbling all over the place sorted now

[jdreamer]

it was the gasket between the carb and the in-let manifold big split was wobbling all over the place sorted now

where'd you get the new gasket Simon?

[jdreamer]

it was the gasket between the carb and the in-let manifold big split was wobbling all over the place sorted now

where'd you get the new gasket Simon?

Just had a poke around on my DF and looked on vagcat. I see there's a flange between carb & manifold rather than a gasket. Mine looks ok and I tried spraying WD40 round it whilst idling, but couldn't really notice any difference, so perhaps my air leak is elsewhere. I only get popping on overrun, not on light throttle.

Regarding the flange, is the carb attached to the flange itself via 2 bolts/studs from underneath and then the flange bolted to the manifold with 4 nuts on the manifold studs? Difficult to see in situ and the vagcat pics don't show how the whole lot attaches up.

Thanks in advance. J

[simony]

got mine from brickwerks yes it attaches to carb with two nuts then bolts on to manifold with four studs

[jdreamer]

Perfect, thanks. J